(1) Field of Invention
The present invention comprises a method for installing a bushing into the end of a transmission shift control linkage of various motor vehicles without damaging the shift cable end or the bushing. The transmission shift control linkage of many motor vehicles generally consists of a shift cable that connects the gear selector or shift lever to the motor vehicle's transmission. The shift cable end is coupled with the gear selector or shift lever via a bushing that allows for the smooth operation of the shift linkage. The bushing installed in the shift cable end of various motor vehicles consists of plastic that dries, rots and becomes brittle over time. The degradation or failure of the bushing allows the shift cable end to become decoupled from the gear selector or shift lever, making it impossible for the operator of the automobile to engage the shift and the transmission.
Presently, the failure of a transmission shift cable end bushing in various motor vehicles requires the removal and replacement of the entire shift cable. This is because the replacement of factory-installed bushings by mechanics generally involve methods utilizing conventional or makeshift tools that deform or otherwise damage the shift cable end or bushing during installation and fail to properly align the bushing with the shift cable end during installation. This results in a sub-standard repair that may not properly couple the shift cable end with the shift lever. Also, degraded factory-installed bushings are occasionally replaced with non-factory, “universal” bushings. Such bushings are not necessarily intended or tailored for any specific application and, when installed, often fail to properly engage the shift cable end, resulting in a sub-standard repair that may not properly couple the shift cable end with the shift lever. Additionally, the supply and labor costs associated with the replacement of the entire shift cable assembly are substantially greater than the supply and labor costs associated with the replacement of the shift cable bushing.
(2) Background Art
There are several bushing installation tools and methods for installing bushings into various housings, including machine housings associated with the internal components of an automatic transmission. An example of such a tool is shown in U.S. Pat. App. No. US2008/0066281, which discloses a pair of linkage bushing installation pliers that operates by coaxially forcing a linkage bushing into the receiving aperture of a machine housing. While such devices fulfill their particular purposes, the application of such tools to the problem of installing a shift cable end bushing without replacing the entire shift cable assembly is akin to using conventional or makeshift tools, which may deform or damage the shift cable end or bushing, resulting in a sub-standard repair that may not properly couple the shift cable end with the shift lever.
Additionally, U.S. Pat. No. 3,537,163 discloses a method for installing a bearing having an external annular groove into a cylindrical bore having an internal annular groove and retaining ring using an installation tool that expands the retaining ring into the annular groove to allow the bearing to pass through the bore until the retaining ring snaps into the external annular groove of the bearing. Such a method and tool have no application to the installation of a bushing in a shift cable end because a shift cable end does not utilize an internal annular groove or retaining ring. Where the method and tool in U.S. Pat. No. 3,537,163 expands a retaining ring to allow for the installation of a bushing in a specific application, the method and tool in the present invention are tailored for use with a shift cable end in that a bushing is compressed to allow it to be installed around an inner annular ridge that is fixed within the shift cable end.